Unfortunately, this only affects the Tommy squad models that were present when the upgrade was purchased. The improved line-of-sight does not carry over to the reinforcing squad members.
Thus, over the course of a game, an upgraded Tommy squad may end up losing their line-of-sight bonus permanently.
I believe this is a similar situation to the one that used to affect Riflemen of the USF Recon Company. Whatever remedy you used to solve the Recon Company bug might also be used to solve this bug as well
